Means for feeding fuel to a combustion chamber



March 16, 1965 C. C. JONES MEANS FOR FEEDING FUEL TO A COMBUSTION CHAMBER Filed Oct. 19, 1962 I 1 I v \Q I T m 0 0 o 0 0 0 Q Q 0 vi ,A/Q

/ Q j j l\ E 0o a ;Q' 2mm Q 1 T o n w m United States Patent 3,173,373 MEANS FOR FEEDING FUEL T!) A (SGM- BUSTEGN QHAMBER Cyril harles Jones, Stanmore, England, assignor to Rotax Limited, London, England Filed Set. 19, 1962, Ser. No. 231,620 Claims priority, application Great Britain, Oct. 20, 1961,

1 Claim. (Cl. 103-52) This invention relates to means for feeding fuel to a combustion chamber, the means being of the kind comprising in combination a hollow body closed at one end and having its other end adapted for connection to a combustion chamber, a hollow shaft extending within said body, a piston slidable on the shaft and having fluidtight seals with the shaft and body, said piston serving to divide the body into first and second chambers at said one and said other end thereof respectively, an inlet to the first chamber adapted for connection to a source of fuel whereby the piston can be moved by fuel pressure to increase the size of the first chamber and fill it with fuel, an inlet to the second chamber adapted for connection to a source of pressure, and means whereby in use pressure applied to the second chamber to move the piston when the first chamber is filled with fuel will cause fuel to be injected into the combustion chamber through the hollow shaft.

The object of the invention is to provide such a means in a convenient form.

According to the invention, means of the kind specified includes a single valve controlling the admission of fuel to the first chamber and the flow of fuel from the first chamber to the interior of the hollow shaft.

The accompanying drawing is a sectional side view illustrating one example of the invention.

Referring to the drawing, there is provided a hollow cylindrical body 1 which at one end is closed by an integral wall 2 and at its opposite end is secured to the wall 3 of a combustion chamber. Secured to the wall 2 is one end of a hollow shaft 4 extending coaxially through the body 1, the interior of the shaft 4 being connected through a valve 5 and an atomiser 6 to the interior of the combustion chamber.

Slidably mounted on the shaft is a piston 7 having fluid-tight seals with the shaft 4 and the body 1, and serving to divide the latter into first and second chambers 8, 9 at said one and other ends thereof respectively.

Within the integral wall 2 is a radial bore 10 adapted for connection to a source of fuel under pressure, the bore communicating through a filter 11 and a valve seating 12, and thence around a loose-fitting valve member 13 with an inlet port 14 extending axially within the wall 2 and communicating with the chamber 8. The valve member 13 is loaded by a spring 15 away from the seating 12, and in this position the end of the valve member 13 closes a further port 16 communicating with the interior of the hollow shaft.

The arrangement is such that fuel fed past the valve member 13 to the chamber 8 fills the chamber 8 with fuel whilst increasing its size until the piston 7 contacts a stop which as shown is the wall 3.

3,173,373 Patented Mar. 16, 1965 The chamber 9 has an inlet 17 adjacent one end thereof, so that the inlet 17 is always in the second chamber irrespective of the position of the piston 7. This inlet 17 is in use connected intermittently to a source of pressure, which may conveniently be the pressure of the air supplied to the combustion chamber. This pressure will move the piston '7 to eject fuel from the chamber 8. Initially there will be a spill of fuel past the valve member 13. However, the latter is formed with a shoulder 13a adjacent the port 14, and the pressure of fuel acting on the shoulder 13a serves to move the valve member 13 against the spring 15 onto the seating 12 so that the chamber 8 is out of communication with the source of fuel. Movement of the valve member 13 simultaneously allows communication to be established between the chamber 8 and the interior of the hollow shaft, so that fuel is fed to the combustion chamber.

Having thus described my invention what I claim as new and desire to secure by Letters Patent is:

Means for feeding fuel to a combustion chamber, comprising in combination a hollow body, means closing one end of said body, the other end of said body being adapted for connection to a combustion chamber, a hollow shaft extending within said body, a piston slidable on said shaft and contacting the body, said piston dividing said body into first and second chambers at said one end and at said other end thereof respectively, fluid-tight seals between said piston and the shaft and body, a port in communication with said second chamber, an inlet at said one end of the body, passage means establishing communication between said inlet and said first chamber and the interior of the hollow shaft, a valve in said passage means, means urging said valve towards a first position in which it establishes communication between said inlet and said first chamber but blocks communication between said first chamber and the interior of said hollow shaft, whereby when said inlet is connected to a source of fuel under pressure said piston will be moved in a direction to decrease the size of said second chamber and fill said first chamber with fuel, means whereby when said second chamber is subjected to a source of pressure supplied by way of said port said piston will move in a direction to decrease the size of said first chamber and will also move said valve to a second position, said valve when in said second position blocking communication between said inlet and said first chamber but establishing communication between said first chamber and the interior of said shaft, and a non-return valve in said hollow shaft through which fuel is fed when said piston is moved in a direction to decrease the size of said first chamber.

References (Iited by the Examiner UNITED STATES PATENTS 2,604,310 7/52 Brown.

2,631,091 3/53 Kuentzel et al 261-82 X 2,685,952 8/54 Hamlin et al 261-82 X 2,770,394 11/56 Mueller 222-389 X 2,804,241 8/57 Mc Dowall et a1 222-335 3,067,810 12/62 Muzic 158-501 LOUIS I. DEMBO, Primary Examiner.

EUGENE F. BLANCHARD, Examiner. 

